There is known, as a medical device in treatment of obesity, a medical device having a sleeve and an anchor, which is to be arranged in a lumen of a gastrointestinal tract to suppresses the digestion and absorption (Patent Literature 1).
When the medical device is used, however, a motility of a gastrointestinal tract, such as peristaltic-movement, is inhibited by the device, and the contact of a food with a gastrointestinal mucosa is blocked. As a result, the atrophy of the gastrointestinal mucosa occurs, and then the atrophied membrane is not recovered. In addition, a problem arises in that the rigid medical device persistently presses an inner wall of the gastrointestinal tract so that the mucous membrane may have a risk to fall into pressure necrosis.